Trimming device



April -27", 1926. 1,582,359

W. H. TROWBRIDGE TRIMMING DEVICE Filed Oct. 4. 1921 SWITCH I 44% n f I ATTOREX Patented Apr. 2 7, 1926.

UNITED STATES 1,582,359 PATENT OFFICE.

'wmnnm n. 'rnownmnen, or rnssarc," NEW mm.

rammme DEVICE.

Application filed October 4, 1921. Serial No. 505,229.

To all whom it may concern:

ming and clipping foliage, and can'be used for trimming bushes, trees and the like, but is more particularly adapted for trimming hedges, where an even and symmetrical appearance is very often desirable.

The invention relates to a device of this kind in which a substantially flat casing acts as a support for a'motor and also for the knife, the device also being adapted to be used by means of ahandle, and 1ts general shape permitting of an observation by the operator of the trimming that he is doing with the machine.

The casing has an open side from which the knife, which rotates, projects for a portion of its rotation, and while thus free from the casing it cuts the foliage with a slicing action without the necessity of a shearing action, that. is, without two opposed cutters coming together, this being due to the high speed imparted by the motor, which is preferably directly connected to the knife and which is operated by current supplied through a conductor, which, for convenience, is preferably arranged along thehandle so as not tointerfere with the operation of the device and which will not become entangled in the shrubbery and the.like.

The invention is illustrated in the accompanying drawing, in which Figure 1 is a perspective view of the device and shows the method of operation on a hedge. Figure 2 is a side view of the'device. Figure 3 is an enlarged side view of the lower part of the casing shown in section, and-Figure 4 is a bottom view with the bottom plate removed.

.The device in general consists of a casin 10 on which is mounted a motor 11 which rotates a knife 12, the knife 12 being adapted to be projected'from the casing during a part of its rotation, and on the ack of the casing is a handle 13, the preferred form of these parts being recited more in detail hereinafter. The knife is preferably of rhomboid form, as shown, so that when the ends are sharpened the cutting edges are tangential to the open end of the casing and to the shaft on which it is mounted.

Thecasing is, tially flat and is preferably. made of two plates, the top plate 14 and the bottom plate 15, the top plate 14 having a bearing 16' through which the shaft 17 of'the motor 11 passes and projects from the under side thereof, the shaft being provided with the knife 12. suitable means, can be screwed on the end of the shaft,.which end of the shaft is also adapted to receive the stud 21 which is screwed through the.

bearing 22 on the lower plate, the stud being preferably pointed or tapered, as at 23, to enter a recess in the end of the shaft 17.

The plates 14 and 15 suitable means, such as screws 24. The top and bottom plates 14 and 15 are of arcuate form, one of them, as, for instance, the top plate 14, having a flange 25 which gives Slll'HClGIlt clearance between the two plates.

for the free operation of the knife, this arcuate form of the top and bottom plates of thecasing thus providing an open end so that the kn1fe,-1n 1ts rotatlon, projects from the The knife is held on the shaft by such as the nut 20 whichfor the most part, substanare held together by l open end and, sweeping through that path of its travel while it is exposed, performs 1ts cutting operation, since the knife operates. at such high speed as to make shearing by two op osed cutters unnecessary. The kni e is preferably mounted so that 1t is supported at its center on the shaft 17, thus having two cutting ends which have the cutting edges 26, these cutting edges bemg arranged at an angle so that they are tangential to the center of rotation of the knife, each cutting edge thus slicing the shrubbery that is-engaged by it, insuring clean cuts and leaving no rough or uneven ed es to the out parts.

he handle 13 is secured preferably to the top of the device, the form handle that is illustrated comprising a lug 27 on the top plate 14 in rear of the motor 11, if desired this In acting as an abutment against which t e motor can rest to stabilize it and prevent undue vibration thereof. The conductor 28 which is used for supplying current to the motor is preferably passed along the handle, usually through the channel 29 arranged lengthwise in the handle or along the outside, exposed, or through a groove the conductor emerging of fastening the.

clip 30 and leading to any suitable source of supply, such-as an outlet box or wall plate 31. A suitable switch 32 is arranged on or in the handle for regulating the operation of the device in so far as supplying electric currentto the motor is concerned.

It will be evident that with this form of device, when operated as illustrated in Figure 1, there is a unitary structure easily portable, and the substantially fiat casing permits an observation, by the operator of the device, of the cutting so that the limi-t the knife, this also permitting the employment of fan-shaped knives and similar cutting devices.

I claim:

1. A trimming devie comprising a substantially fiat casing made of two plates of arcuate form, the casing having an open end, a shaft passing into the casing, a knife secured at its centre on the shaft and fitting between the plates so as to clear the space between them wheniin'side the casing and to perform its cutting operation when it swings free of the casing, the blade being of rhomboid form with its ends sharpened to form cutting edges parallel to lines tangential to the shaft and to the open end of the on the second plate to engage the end of the shaft, a flat knife on the shaft fitting between the plates and adapted to be projected when rotating so as to perform its cutting operation free of the casing, a boss on one of said plates, a handle projecting from the boss, and a conductor passing along the handle and supported thereby and connected to the motor.

3. A trimming device comprising a casing formed of two plates spaced apart, said plates being of arcuate form, a motor mounted on one plate and having a shaft projecting through the plate, a stud secured in the second plate and adapted to engage the end of the shaft, a flat knife with a cutting edge that is parallel to lines' tangential to the shaft, said knife being securedon the shaft, the shaft being disposed so that the knife swings free of the casing to perform its cutting operation, a handle secured to one of the plates in rear of the motor, and a conductor connected to the motor and supported along said handle.

In testimony that I claim the foregoing, I have hereto set my hand, this 27th day of July, 1921.

WM. H. TROWBRIDGE. 

